-> PortScanner added

Networking/PortScanner/UDPPortScanner.cs

@@ -0,0 +1,94 @@
+using Networking.Pages;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;
+using System.Net.Sockets;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace PortScanner
+{
+     class UDPPortScanner : PortScannerBase
+     {
+          // The UDP client used for scanning a port
+          private UdpClient udpClient;
+
+          // Constructor - use base constructor
+          public UDPPortScanner() : base()
+          {
+          }
+
+          // TODO:
+          public async override Task<bool> CheckOpenAsync(CancellationToken ct)
+          {
+               // We are using a UDP client to see whether the port is open or not
+               // Therefore, the absence of a response means that the port is open
+               // If there is any respone, it is closed
+               using (udpClient = new UdpClient())
+               {
+                    bool returnVal;
+                    try
+                    {
+                         // Connect to the server
+                         udpClient.Connect(Hostname, Port);
+
+                         // Set the timeout
+                         udpClient.Client.ReceiveTimeout = Timeout;
+
+                         // Sends a message over UDP
+                         Byte[] sendBytes = Encoding.ASCII.GetBytes("Are you open?");
+                         udpClient.Send(sendBytes, sendBytes.Length);
+
+                         // IPEndPoint object will allow us to read datagrams sent from any source.
+                         // Port 0 means any available port
+                         IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, 0);
+
+                         // Asynchronously begin receiving
+                         var result = udpClient.ReceiveAsync();
+                         if (await Task.WhenAny(result, Task.Delay(Timeout, ct)) == result)
+                         {
+                              Console.WriteLine(Encoding.ASCII.GetString(result.Result.Buffer));
+                              returnVal = false;
+                         }
+                         else
+                         {
+                              // There was no response, we will consider this port as open
+                              returnVal = true;
+                         }
+                         udpClient.Close();
+                         return returnVal;
+                    }
+                    catch (SocketException e)
+                    {
+                         Console.WriteLine("Error Code: " + e.ErrorCode);
+
+                         switch (e.ErrorCode)
+                         {
+                              case 10054:
+                                   returnVal = false;
+                                   break;
+
+                              case 11001:
+                                   returnVal = false;
+
+                                   // Display an error message on the main thread
+                                   MessageBox.Show(
+                                       "Hostname could not be resolved.",
+                                       "Connection Error",
+                                       MessageBoxButtons.OK,
+                                       MessageBoxIcon.Error);
+                                   break;
+                              default:
+                                   returnVal = true;
+                                   break;
+                         }
+                    }
+                    udpClient.Close();
+                    return returnVal;
+               }
+          }
+     }
+}